Iron Neck Power Bands are made from a durable latex rubber, and come in six different color-coded resistance levels. XX-Light and X-Light bands offer lighter resistance for general conditioning and rehab. Light and Medium bands deliver moderate resistance for banded bench presses and squats + more intense mobility work. Heavy and X-Heavy bands offer stronger resistance for experienced, high-level athletes looking to get more out of their squats, deadlifts, leg presses, shrugs, etc. All Iron Neck Power Bands measure the same 41" in length and feature exclusive Iron Neck branding. Order individual bands or bundles to accomplish your training goals, whether you just want a better way to stretch in your home gym, or you need to fully equip a large training facility with a variety of bands for multiple uses.